German Patent Application No. DE 35 33 085 describes a metering valve for the metering of fluids or gases, especially an injection valve for fuel-injection systems in internal combustion engines, which includes a piezo stack actuator whose linear deformation in response to the application of an excitation voltage is transmitted to a valve needle which controls a metering orifice and determines the valve lift of the valve needle. The substance to be metered is supplied via a supply line which is designed in the form of a deep-hole bore in the valve body.
Disadvantageous in the metering valve described in German Patent Application No. DE 35 33 085 is the floating suspension of the hydraulic coupler between fuel intake and actuator, which exposes the coupler to fluctuations in the fuel pressure. The electrical lines required for the contacting of the actuator must be run in a complicated manner to prevent tensile stressing due to the positional changes. Furthermore, the lines have to be installed around the coupler, which makes them both longer and also increases the installation space. The valve housing becomes bulky as a result and in turn requires larger installation space in the cylinder head.